This invention relates to an air-cooled type absorption refrigeration system.
In, for example, U.S. Pat. No. 4,467,623, a conventional air-cooled absorption refrigeration system is described which includes a generator, a condenser, an evaporator, and an absorber, with the absorber having a plurality of vertical tubes for receiving, at top ends thereof, a strong absorbent solution from the generator and for receiving, at bottom ends thereof, refrigerant vapor from the evaporator whereby the refrigerant vapor is absorbed by the strong absorbent solution to form a weak absorbent solution.
However, since the volume flow rate of the refrigerant vapor flowing from the evaporator to the absorber is very high, the refrigerant vapor remains at the bottom end of the vertical tube absorber and does not readily flow up inside of the vertical tubes. Thus, the refrigerant vapor does not reach the center and the vicinity of the top of the vertical tube absorber, and the absorption effect is not efficiently exhibited at such sections of the absorber.
Also, since the volume flow rate of the refrigerant vapor flowing from the evaporator to the absorber is very high as described above, a sufficient passage area for the refrigerant vapor is not obtained only with the bottom end of the vertical tube absorber, and it is not always possible to make the refrigerant vapor smoothly flow to the absorber. As a result, the vapor pressure inside of the evaporator becomes high, evaporation of the refrigerant is suppressed, and the chilling effect decreases. Further, since there is provided only one position for taking out the vapor from the evaporator, the flow condition of the refrigerant vapor inside of the evaporator is deteriorated, and the chilling effect decreases.
The primary object of the present invention is to provide an air-cooled absorption refrigeration system wherein the refrigerant vapor evaporated in the evaporator reaches the whole region of the air-cooled vertical tube absorber.
Another object of the present invention is to provide an air-cooled absorption refrigeration system wherein a weak absorbent solution is created by the air-cooled vertical tube absorber.
A further object of the present invention is to provide an air-cooled absorption refrigeration system wherein the refrigerant vapor is smoothly supplied to the air-cooled vertical tube absorber.
To attain the above objects, according to the present invention, the evaporator and the vertical tube absorber are made to communicate with each other through communication passages arranged at the top and bottom or the top, bottom and the central parts, respectively, of the absorber so as to cause a downward flow of the absorbent solution to generate through the vertical tubes whereby the refrigerant vapor received from the top end of the tubes is directed downward to be absorbed by the absorbent solution .